On 17/05/2021 at 16:31, sepulchrave said:

 

Black smoke is unburnt fuel, as @KenONeill correctly pointed out, it's overfuelling, however the reason is trickier to divine. I'd change the ECT sensor then the FTS.

Do u know what's the normal Air/fuel ratio? Cause wanna check it, but can't find any info about it 

20 minutes ago, vonweiser said:

Do u know what's the normal Air/fuel ratio? Cause wanna check it, but can't find any info about it 

 

It's not as simple as that, complete combustion depends on temperature, pressure and droplet size, small variations in these parameters affect flame speed quite markedly, diesel burns much slower than petrol which is why diesel engines can't rev like petrol engines do.

36 minutes ago, vonweiser said:

Do u know what's the normal Air/fuel ratio? Cause wanna check it, but can't find any info about it 

I think diesels generally go by EGT rather than AFR like petrols do. The throttle in a diesel is metering fuel into the engine, controlling speed that way so I dont think afr is much use. 

2 hours ago, vonweiser said:

Do u know what's the normal Air/fuel ratio?

No, because there isn't a design air/fuel ratio on a diesel engine. The volume of fuel injected rather than the opening of the throttle venturi is what controls the engine speed. That doesn't alter the fact that black smoke is a symptom of the engine being overfuelled resulting in incomplete combustion and soot as per my reply to your original posting.

As said previously, black smoke is due to unburnt fuel.

Rather than excess fuel, it can be due to lack of oxygen available to burn the fuel.

 

If the EGR is stuck open, combustion could be getting stifled by the lack of oxygen due to excess inert EGR exhaust gas.

 

Just something worth checking.

 

 

Add cam timing.